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Unrated severityNVD Advisory· Published Apr 3, 2024· Updated Jan 5, 2026

can: j1939: prevent deadlock by changing j1939_socks_lock to rwlock

CVE-2023-52638

Description

In the Linux kernel, the following vulnerability has been resolved:

can: j1939: prevent deadlock by changing j1939_socks_lock to rwlock

The following 3 locks would race against each other, causing the deadlock situation in the Syzbot bug report:

  • j1939_socks_lock
  • active_session_list_lock
  • sk_session_queue_lock

A reasonable fix is to change j1939_socks_lock to an rwlock, since in the rare situations where a write lock is required for the linked list that j1939_socks_lock is protecting, the code does not attempt to acquire any more locks. This would break the circular lock dependency, where, for example, the current thread already locks j1939_socks_lock and attempts to acquire sk_session_queue_lock, and at the same time, another thread attempts to acquire j1939_socks_lock while holding sk_session_queue_lock.

NOTE: This patch along does not fix the unregister_netdevice bug reported by Syzbot; instead, it solves a deadlock situation to prepare for one or more further patches to actually fix the Syzbot bug, which appears to be a reference counting problem within the j1939 codebase.

[mkl: remove unrelated newline change]

Affected products

63

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

5

News mentions

0

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